package com.xiaobias.a02;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;

import javax.annotation.Resource;

public class TestBeanFactory {
    // 二、容器实现

    // 给BeanFactory添加一些常用的后处理器,将后处理器加到BeanFactory

    // 提前准备好所有单例对象
    // 2. ApplicationContext 的常见实现和用法
    // 3. 内嵌容器、注册 DispatcherServlet
    public static void main(String[] args) {
        // 1.BeanFactory实现的特点
        DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
        // bean的定义(class，scope，初始化，销毁)
        AbstractBeanDefinition beanDefinition = BeanDefinitionBuilder.genericBeanDefinition(Config.class).setScope("singleton").getBeanDefinition();
        beanFactory.registerBeanDefinition("config", beanDefinition);
        // 获取内置后处理器
        AnnotationConfigUtils.registerAnnotationConfigProcessors(beanFactory);
        // BeanFactory 后置处理器主要功能，补充了一些 bean 定义
        beanFactory.getBeansOfType(BeanFactoryPostProcessor.class).values().forEach(beanFactoryPostProcessor -> {
            beanFactoryPostProcessor.postProcessBeanFactory(beanFactory);
        });
        // Bean 后处理器 ，针对 bean 的生命周期的各个阶段提供扩展，例如 @Autowired @Resource   这里是建立 BeanFactory 和后处理器的联系
        beanFactory.getBeansOfType(BeanPostProcessor.class).values().stream()
                .sorted(beanFactory.getDependencyComparator())
                .forEach(beanPostProcessor -> {
            System.out.println(">>>>>>" + beanPostProcessor);
            beanFactory.addBeanPostProcessor(beanPostProcessor);
        });
        for (String name : beanFactory.getBeanDefinitionNames()) {
            System.out.println(name);
        }
        // 准备好所有的单例
        beanFactory.preInstantiateSingletons();
        System.out.println(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
        // 给 BeanFactory 添加一些常用的后置处理器
//        System.out.println(beanFactory.getBean(Bean1.class).getBean2());
        System.out.println(beanFactory.getBean(Bean1.class).getInter());
        // 学到什么：
        // a. beanFactory 不会做的事
        //      1. 不会主动调用 BeanFactory 后置处理器
        //      2. 不会主动添加 Bean 后置处理器
        //      3. 不会主动初始化单例
        //      4. 不会解析BeanFactory 还不会解析 ${} 与 #{}

        System.out.println("CommonAnnotationBeanPostProcessor Ordered: " + (Ordered.LOWEST_PRECEDENCE - 3));
        System.out.println("AutowiredAnnotationBeanPostProcessor Ordered: " + (Ordered.LOWEST_PRECEDENCE - 2));

    }

    @Configuration
    static class Config {

        @Bean
        public Bean1 bean1() {
            return new Bean1();
        }

        @Bean
        public Bean2 bean2() {
            return new Bean2();
        }

        @Bean
        public Bean3 bean3() {
            return new Bean3();
        }

        @Bean
        public Bean4 bean4() {
            return new Bean4();
        }
    }

    interface Inter {

    }

    static class Bean3 implements Inter {}

    static class Bean4 implements Inter {}

    static class Bean1 {
        private static final Logger logger = LoggerFactory.getLogger(Bean1.class);

        @Autowired
        private Bean2 bean2;

        // 后处理器的顺序有关
        @Autowired
        @Resource(name = "bean4")
        private Inter bean3;

        public Inter getInter() {
            return bean3;
        }

        public Bean1() {
            logger.debug("构造 Bean1()");
        }

        public Bean2 getBean2() {
            return bean2;
        }
    }

    static class Bean2 {

        private static final Logger logger = LoggerFactory.getLogger(Bean2.class);

        public Bean2() {
            logger.debug("构造 Bean2()");
        }

    }
}
